Curve Mode
From ZBrush Info
A model with a major use of Curve. Model by Marco Plouffe.
The new Curve Mode will allow you to draw a curve and then sweep your stroke along it. Depending on the selected options, the curve will be deformable and/or movable across the mesh.
When created, the Curve can be applied to any 3D Brush. This allows you to apply deformation to the mesh beneath the curve or to modulate a mesh using the curve settings.
The deformation attached to the curve can also being updating by moving the curve: ZBrush will update the resulting stroke, letting you refine your design and doing fine tuning. As soon as you create a new curve or switch to another operaton, the curve won't be editable anymore. It means that until you are in your current curve, you can do as much change as you wish.
Several custom brushes with Curve mode activated have been included with ZBrush 4R2. These allow effects such as duplicating patterns onto a mesh or even the insertion of other meshes for use with DynaMesh. These sample brushes can be used as good starting points to create your own custom Curve brushes or to better understand the great potential introduced by this Stroke setting. Brushes that have Curve Mode activated can be located in the Brush palette or in the LightBox >> Brush >> Curves folder.
The same model as above, from a different point of view. Model by Marco Plouffe.
Note: The Curve mode is different from the LazyMouse Spline and Path options. These other settings snap or constrain the brush action along the spline or path, while the Curve mode applies the brush along the length of the curve.
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Curve Creation and Manipulation
To create a Curve Stroke, first select the brush that you want to apply the Curve modifier to. Then enable Curve Mode, located in the Stroke palette. If needed, change the Curve Mode settings and options, located below the Curve Mode switch.
Click and drag on your surface to draw a stroke over your model.The number of internal points making up the curve can be modified using the Curve Step slider setting.
Note: The curve must be started on a model (active or not), but can be continued in the empty space of the document.
Upon releasing your mouse/pen click your stroke corresponding to your current brush will be automatically created and you you will see a small circle at either end of the curve. These are manipulators to control the curve, similar to the circles on TransPose Action Line. By hovering over the curve without clicking on it, you will attract the curve to move with your cursor. This deformation or movement of the curve will also be affected by the Bend and Snap options found in the Curve Mode settings.
You will notice that the brush circles will change of color from its default red color to a cyan color when hovering the curve. This cyan color mean that you are using this cursor to manipulate the curve and will use its size and falloff setting to deform it. A small circle will do small deformation on the curve while a larger circle will apply a large deformation of the curve. To change the cursor settings, change te Curve Edit Radius and Focal Shift sliders values, located in the Stroke palette.
Note: To avoid going in the Stroke palette to modify the Curve Edit and Curve Focal Shift values, use the corresponding hotkey when your cursor is hovering the curve: S for Curve Edit radius and O for Curve Edit Focal Shift.
If you move your cursor off the model and into open document space, contact with the curve will be lost. When this happens you will then be able to draw another curve along the surface. An alternative is to tap your cursor quickly on your model surface,to delete the current curve.
Whenever you draw a new curve, the previous one will disappear and be replaced with the new curve. Curve Mode remains active until you turn it off or select a brush that does not have Curve Mode activated. If Curve mode is re-enabled after being turned off, the most recently created curve will be visible once again.
All curves must start on a 3D model, even if you wish to sweep it off the surface. However, immediately after creating a curve you can hold the Space Bar which allows you to move the curve relative to the screen/canvas. This includes being able to move the curve off the model, making it possible to easily create 3D geometry when combined with the Insert brushes. Combining Curve Mode and the Insert brushes with DynaMesh can give you an artistic freedom to create with no boundaries.
Notes: If you want to apply a curve to a Mask or Smooth brush, you may do so by holding the appropriate modifier key (CTRL or ALT) while changing the Curve mode options. If you wish to apply these options to a different Mask or Smooth brush, you must first select that brush and then hold the modifier key to gain access to the brush’s settings.
By default, the curve will always snap to the surface even if the Snap setting is disabled. If you wish to create a curve which will snap to the screen working plane, enable the Once Z mode, located in the Picker Palette. Don’t forget to return to the original settings after drawing your curve, as the Picker options are global to ZBrush rather than linked to the selected brush.
Curve editing
Your curve, after its creation, can update the current stroke attached to the current brush, like mentionned above. It means that as soon as your Curve stroke is done, the brush will be applied directly on your model. If you click and drag your curve or its two extremities manipulators, this same stroke will be updated according to your existing curve.
To take an example, if you use a brush which is used to polypaint your model and create a curve stroke, as soon as you release your cursor, you will see your stroke color applied on the surface of your model. Then manipulate your curve: the current polypainting will be move to the new curve location or shape. This ability is extremly powerful when you need to do fine tuning edits on your model, whatever it's an alpha pattern on your surface or a polypainting.
Snapshot of curves
If you wish to reuse your existing curve to create a copy of its current stroke, you can drop it on the model and continue using it with a new stroke.
To do this operation, you must do a Snapshot of your current stroke: it will collapse its result on the geometry and will let you continuing using the same curve which will, of course, apply directly a new stroke on your model.
Note: A good tip is to use a curve and doing a snapshot of its result, then, still with the same curve, switching to a new brush and apply the result of this new brush to the same stroke. It is a good way to create complex shape or apply complex sculpting effect by overlapping different brushes together.
Curve Mode Settings and Options
The Curve mode, below the Lazy mouse in the Stroke palette.
Curve Mode
The Curve Mode Allows allows a curve to be applied to the currently selected brush. As with other Stroke settings, this option is enabled per brush and is not globally applied to all brushes.
As Line This As Line mode constrain the curve as a line, at its creation time but not at its editing time.
Curve Step The Curve Step defines the roundness of the Curve when created. It also sets the space between each point making up the curve when it is drawn. A low setting results in a short distance between steps and so will create a smooth stroke with many points. A high setting applies a stroke with larger steps and fewer points.
The Step setting with three different values from left to right: 0.1, 0.5 and 0.9. The lower setting create smoother curves but more points.
Bend Mode (enabled by default)
A bend can be applied by hovering over any of the points along the curve and then moving your cursor to pull the point and create the desired angle.
The amount of bend at the cursor location is defined by the Curve Falloff settings, located at the bottom of the Curve sub-palette. A Curve Falloff which has the point at the top left will produce a rounded curve deformation while a curve falloff which goes to the bottom right of the curve line will produce an angular curve.
Snap Mode The Snap Mode enables the curve’s ability to snap to the underlying surface when being manipulated or while applying the associated brush.
Intensity Mode (enabled by default) The Intensity Mode enables the usage of variable intensity when the brush stroke is applied to the curve. To create a constant stroke along the curve’s length, disable this setting. When the Intensity Mode switch is disabled a consistent intensity will be applied along the entire curve.
Size Mode The Size Mode enables the variation of the size (elevation) of the brush along the curve. The variation will be applied from the starting point to the ending point of the curve.
To see the effect of Size mode, it is recommended to experiment with the InsertCylinder brush and various Curve Falloff settings combined with Size mode:
- By default, when Size mode is off the cylinder is inserted along the curve with a constant size.
- When Size mode is on with its default settings, the cylinder is at its full size at the origin of the curve and at 0% of its size at the end point.
- Change the curve falloff to the opposite shape (from top left to bottom right) and the Cylinder will be at its full size at the end point and 0% of its size at the beginning.
- Now edit the curve in different ways to see the results you can come up with.
Two different Falloff curves which affect the size of the brush along the Curve.
Remember you can apply these settings to a traditional sculpting brush for similar effects.
Curve Falloff This curve setting can be used to modulate two modes: Bend mode and Size mode.
- When used with Bend mode, it will let you define smoothness or pinching of the curve. See the Bend Mode section above for more information.
- When used with Size mode, it will let you define the shape of the deformation when the brush is applied along the Curve. Top to bottom within the box defines strength as values from 100% at the top to 0% at the bottom. Left to right defines the position along the curve from its origin at the left to its termination at the right. See the Size Mode section above for more information.
The Curve Falloff settings.
Note about the Insert brushes and Curve mode
As mentioned in the Size Mode section, it is possible to combine a curve with the Insert brushes. When drawing with an Insert brush the object will be stretched along the curve, deforming the mesh along that drawn out curve. It is not possible to alter/edit the mesh as it is being stretched along the curve. However, it is possible first select that mesh in the Tool palette and then edit it before returning to the model that you are going to insert it into. For example, you can change the inserted object’s orientation by temporarily switching to it and then changing its default position and orientation via the Tool >> Preview menu.
Curve Edit Radius slider The Curve Edit Radius slider changes the size of the brush when editing its curve. It is similar to the default brush Draw Size slider located in the Draw palette, but applied to the Curve editing. A larger Edit Radius size will deform globally the curve while a smaller size will deform locally the curve.
Curve Edit Focal Shift slider The Curve Edit Focal Shift slider changes the falloff of the brush when editing its curve. It is similar to the default brush Focal Shift slider located in the Draw palette, but applied to the Curve editing. A larger Focal Shift size will deform smoothly the curve while a smaller size will pinch the curve.
Max Points slider The Max Points slider defines a maximum point on the curve after its creation. This setting is useful when you want to apply a predefine number of patterns along the curve.
